By Jamie Martin
The beginning of lactation is a critical time for dairy cows, and proper calcium management plays an important role in their success. Hypocalcemia or milk fever occurs when blood calcium levels fall around calving and can lead to health and production problems.
“Historically, when we think of hypocalcemia, it’s those cows that go down and are unable to stand around the time of calving,” said Jen Roberts, DVM, Boehringer Ingelheim. “They may also have difficulty calving because they don’t have enough blood calcium for uterine contractions to deliver the calf. Those are the cows we see.”
Some cows show obvious signs such as weakness or difficulty standing. However, many cows experience subclinical hypocalcemia which is harder to notice. Even without visible symptoms, these cows may have lower feed intake, reduced milk production, and a higher risk of retained placenta and infections.
“Subclinical hypocalcemia, by definition, is something you don’t typically see, especially in healthy cows, which are the most susceptible,” said Curt Vlietstra, DVM, Boehringer Ingelheim. “If you want to address it, you need to be aware that it is a problem.”
Because subclinical hypocalcemia is difficult to detect, prevention is essential. Managing cows well during the pre-fresh period helps prepare their bodies for the demands of calving and milk production. Nutrition is especially important for older and high-producing cows.
One common prevention strategy is feeding a negative dietary cation-anion difference diet during the last few weeks before calving. This diet helps improve calcium regulation and lowers the risk of hypocalcemia during early lactation.
After calving, cows experience their lowest blood calcium levels within the first day. Providing an oral calcium bolus during this time helps support calcium needs and improves the transition into lactation. A second bolus given within 12 to 24 hours can further support high-producing cows and help maintain normal body functions.
“After calving, supplementing cows with an oral, rapidly dissolving, readily available calcium bolus will help support their needs,” said Dr. Roberts. “If we’re not supporting those cows and providing additional calcium to keep them going smoothly through that transition, it can negatively impact their lactation and longevity in the herd. We need to ensure we provide supplemental calcium to support cows, so they can get lactation off to the best start.”
The type of calcium in a bolus matters. Acidogenic forms such as calcium chloride and calcium sulfate are absorbed quickly and encourage the body to release calcium from bone reserves. Alkalogenic forms like calcium carbonate are absorbed more slowly and are less effective during this period.
Using a high-quality bolus with the right calcium balance and easy to administer design improves safety and results. When combined with proper nutrition, these practices help reduce health problems, improve milk production and support long term herd performance.
Photo Credit: gettyimages-jesp62
Categories: National